Reinforcement history: a concept underutilized in behavior analysts.

Some years ago Underwood (1964) grappled with the problem of explaining his finding that rate of forgetting was not a function of the rate of learning but rather seemed to reflect the level of learning achieved. He likened different rates of learning to filling an Erlenmeyer flask of water at different rates and the process of forgetting to the rate of evaporation, which in turn is a function of the exposed surface area. Since an Erlenmeyer flask is cone-shaped, the surface area becomes smaller as the flask is filled, thus the greater the amount of learning achieved, or water added, the less the rate of evaporation independent of how quickly or slowly the flask was filled. I give this example because it is such a clear description of history kept simple, in the psychological process of learning and forgetting. Indeed it is as simple as Charles Dickens' description of how students are to be taught, that is, by considering them to be "little vessels...ready to have imperial gallons of facts poured into them until they were full to the brim" (Dickens, 1961, p. 12). The object of this paper is to show how our neglect in specifying the history of reinforcement and other behavior analytic concepts has resulted in our ceding much of our field to cognitive psychologists even though our knowledge of conditioning enables us to study it more thoroughly than they can.